In recording head technology, much thought is put into the positioning of the write/read devices on the head. The positioning of these devices is important in order to meet recording throughput and capacity requirements in the most efficient and inexpensive way possible while making the system robust to variations that exist in areas such as head manufacturing, tape to head azimuth (angle), and media width.
As recording densities increase, these variations become an even larger problem and make it increasingly difficult to properly position the writers and readers on the media which can lead to write and/or read position errors. One way to minimize position errors caused by these variations is to reduce the write and/or read device set span on the media. This is typically done by reducing the spacing between the individual write and/or read magnetic elements within the device set and thereby reducing the overall device set span. This method, however, complicates the head manufacturing process. In addition, moving the magnetic elements closer together within the device set increases the likelihood of crosstalk between the elements which can negatively impact drive write and/or read performance.
An alternate method of reducing device set span without these negative side effects is described here. This new method is accomplished by splitting the write and/or read device set into two sets, with each having half the number of magnetic elements and half the span of the original device set. The spacing between the individual elements within the two new device sets remains the same as the spacing between the elements in the original device set. Each of these smaller device sets would then be independently positioned on the media for writing and/or reading. FIG. 1 provides an illustration of the effects of media width variations on the spacing of the data tracks on the media. Magnetic tape 10 includes a plurality of data tracks 12 which are separated by a distance d. Expansion of magnetic tape 10 as depicted by arrow “A” leads to widening of the tape which is accompanied by widening of the spacing de between the data tracks. Contraction of magnetic tape 10 as depicted by arrow “B” leads to a narrowing of the tape which is accompanied by a decrease in the spacing dc between data tracks. Tape tension, temperature, and humidity are major contributors to tape expansion and contraction effects.
As the densities at which data is recorded onto or read from the media increase, new methods of compensating for variations in the tape drive system such as variations in head manufacturing, tape to head azimuth (angle), and media width are required. There is a need for improved magnetic read/write heads and for improved methods of positioning the head magnetic elements on the storage media. In particular, a new method is needed for independently actuating and positioning dual write and/or read device sets located on a single recording head to reduce the span of those device sets on the media.